1. Field of the Present Invention
The present invention relates to spotlights, and more particularly to a spotlight using an electrically-conductive slip ring and having 360-degree horizontal lighting.
2. Description of Related Art
Referring to FIG. 1, a conventional spotlight 90 is a lamp capable of changing its lighting direction vertically and horizontally. The spotlight 90 comprises a lamp housing 91 and a support 92 pivotally supporting the lamp housing 91 from below.
In the lamp housing 91, a partition 94 divides the interior of the lamp housing 91 into a lamp compartment 91a and a driving-device compartment 91b. 
A lamp assembly 95 is pivotally installed in the lamp compartment 91a. A vertical driving device 96 is installed in the driving-device compartment 91b and affixed to the middle partition 94. A horizontal driving device 97 is fixedly installed inside the support 92.
A curved rack 95a is provided behind the lamp assembly 95, for the vertical driving device 96 to engage and move the lamp assembly 95. In response to the driving force from the vertical driving device 96, the lamp assembly 95 tilts up and down in the lamp compartment 91a of the lamp housing 91, so as to provide a vertically changeable lighting angle.
A ring gear 91c is provided below the lamp housing 91, for the horizontal driving device 97 to engage and move the lamp assembly 95. In response to the driving force from the horizontal driving device 97, the lamp housing 91, together with the lamp assembly 95 installed in its lamp compartment 91a, swivels right and left against the support 92, so as to provide a horizontally changeable lighting angle.
The conventional spotlight 90 is powered through a cable 98. The cable 98 includes three sets of power cords. The first power cord set 98a is electrically connected to the lamp assembly 95 of the conventional spotlight 90, for powering the illumination of the lamp assembly 95. The second power cord set 98b is electrically connected to the motor of the vertical driving device 96 of the conventional spotlight 90, for powering the motor to rotate forward or reversely. The third power cord set 98c is electrically connected to the motor of the horizontal driving device 97 of the conventional spotlight 90, for powering the motor to rotate forward or reversely.
However, in use, when the conventional spotlight 90 tries to make a horizontal 360-degree rotation, the three power cord sets 98a, 98b and 98c of the cable 98 tend to twist and get pulled apart. For this reason, the conventional spotlight 90 is limited by the three power cord sets 98a, 98b and 98c and fails to provide 360-degree horizontal illumination.